Radiation image read-out method and apparatus

Abstract

Stimulating rays are linearly irradiated onto an area of a stimulable phosphor sheet, and light emitted by the sheet is detected with a line sensor. A device for irradiating the stimulating rays comprises laser diodes and a cylindrical lens. The laser diodes are located such that laser beams produced by the laser diodes as the stimulating rays stand in a row along the length direction of the linear area of the sheet exposed to the stimulating rays. Each laser diode is located in an orientation such that a beam spread direction normal to a junction plane approximately coincides with the direction, along which the laser beams stand in a row. The cylindrical lens converges each laser beam only in a plane normal to the direction, along which the laser beams stand in a row, and onto the sheet.

1. A radiation image read-out method, comprising the steps of:
 i) linearly irradiating stimulating rays through a cylindrical lens onto an area of a stimulable phosphor sheet, on which a radiation image has been stored, with stimulating ray irradiating means, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored thereon during its exposure to radiation, 
 ii) receiving light, which is emitted by the stimulable phosphor sheet, with a line sensor comprising a plurality of photoelectric conversion devices arrayed along the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, the received light being subjected to photoelectric conversion performed by the line sensor, and 
 iii) moving the stimulable phosphor sheet with respect to the stimulating ray irradiating means and the line sensor and in a direction intersecting with a length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 wherein the stimulating ray irradiating means comprises: 
 a plurality of laser diodes located such that laser beams, which have been produced by the laser diodes and act as the stimulating rays, stand in a row along the length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, each of the laser diodes being located in an orientation such that a beam spread direction, which is normal to a junction plane, approximately coincides with the direction, along which the laser beams stand in a row, and 
 the cylindrical lens operable to converge each of the laser beams, which have been produced by the laser diodes, only in a plane normal to the direction, along which the laser beams stand in a row, and onto the stimulable phosphor sheet. 
 
     
     
       2. A radiation image read-out method, comprising the steps of:
 i) linearly irradiating stimulating rays through a cylindrical lens onto an area of a stimulable phosphor sheet, on which a radiation image has been stored, with stimulating ray irradiating means, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored thereon during its exposure to radiation, 
 ii) receiving light, which is emitted by the stimulable phosphor sheet, with a line sensor comprising a plurality of photoelectric conversion devices arrayed along the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, the received light being subjected to photoelectric conversion performed by the line sensor, and 
 iii) moving the stimulable phosphor sheet with respect to the stimulating ray irradiating means and the line sensor and in a direction intersecting with a length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 wherein the stimulating ray irradiating means comprises: 
 a plurality of laser diodes located such that laser beams, which have been produced by the laser diodes and act as the stimulating rays, stand in a row along the length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 the cylindrical lens for converging each of the laser beams, which have been produced by the laser diodes, only in a plane normal to the direction, along which the laser beams stand in a row, and onto the stimulable phosphor sheet, and 
 optical devices, each of which is located between one of the laser diodes and the cylindrical lens and scatters the laser beam having been produced by the corresponding laser diode; wherein each of the laser diodes are located in an orientation such that a beam spread direction, which is normal to a junction plane, approximately coincides with the direction, along which the laser beams stand in a row. 
 
     
     
       3. A radiation image read-out method, comprising the steps of:
 i) linearly irradiating stimulating rays through a cylindrical lens onto an area of a stimulable phosphor sheet, on which a radiation image has been stored, with stimulating ray irradiating means, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored thereon during its exposure to radiation, 
 ii) receiving light, which is emitted by the stimulable phosphor sheet, with a line sensor comprising a plurality of photoelectric conversion devices arrayed along the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, the received light being subjected to photoelectric conversion performed by the line sensor, and 
 iii) moving the stimulable phosphor sheet with respect to the stimulating ray irradiating means and the line sensor and in a direction intersecting with a length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 wherein the stimulating ray irradiating means comprises: 
 a plurality of laser diodes located such that laser beams, which have been produced by the laser diodes and act as the stimulating rays, stand in a row along the length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, each of the laser diodes being located in an orientation such that a beam spread direction, which is normal to a junction plane, approximately coincides with the direction, along which the laser beams stand in a row, 
 the cylindrical lens for converging each of the laser beams, which have been produced by the laser diodes, only in a plane normal to the direction, along which the laser beams stand in a row, and onto the stimulable phosphor sheet, and 
 optical devices, each of which is located between one of the laser diodes and the cylindrical lens and scatters the laser beam having been produced by the corresponding laser diode. 
 
     
     
       4. A method as defined in  claim 1 ,  2 , or  3  wherein the plurality of the laser diodes are located such that the laser beams, which have been produced by the laser diodes adjacent to each other among the plurality of the laser diodes, stand in a row so as to have an overlapping region, at which the laser beams overlap each other. 
     
     
       5. The radiation image read-out method as claimed in any one of  claims 1 – 3 , wherein the cylindrical lens comprises a single continuous cylindrical surface. 
     
     
       6. A radiation image read-out apparatus, comprising:
 i) stimulating ray irradiating means for linearly irradiating stimulating rays through a cylindrical lens onto an area of a stimulable phosphor sheet, on which a radiation image has been stored, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored thereon during its exposure to radiation, 
 ii) a line sensor, which comprises a plurality of photoelectric conversion devices arrayed along the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, and 
 iii) sub-scanning means for moving the stimulable phosphor sheet with respect to the stimulating ray irradiating means and the line sensor and in a direction intersecting with a length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 wherein the stimulating ray irradiating means comprises: 
 a plurality of laser diodes located such that laser beams, which have been produced by the laser diodes and act as the stimulating rays, stand in a row along the length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, each of the laser diodes being located in an orientation such that a beam spread direction, which is normal to a junction plane, approximately coincides with the direction, along which the laser beams stand in a row, and 
 the cylindrical lens for converging each of the laser beams, which have been produced by the laser diodes, only in a plane normal to the direction, along which the laser beams stand in a row, and onto the stimulable phosphor sheet. 
 
     
     
       7. A radiation image read-out apparatus, comprising:
 i) stimulating ray irradiating means for linearly irradiating stimulating rays through a cylindrical lens onto an area of a stimulable phosphor sheet, on which a radiation image has been stored, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored thereon during its exposure to radiation, 
 ii) a line sensor, which comprises a plurality of photoelectric conversion devices arrayed along the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, and 
 iii) sub-scanning means for moving the stimulable phosphor sheet with respect to the stimulating ray irradiating means and the line sensor and in a direction intersecting with a length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 wherein the stimulating ray irradiating means comprises: 
 a plurality of laser diodes located such that laser beams, which have been produced by the laser diodes and act as the stimulating rays, stand in a row along the length direction of the linear area of the stimulable phosphor sheet exposed, to the linear stimulating rays, 
 the cylindrical lens for converging each of the laser beams, which have been produced by the laser diodes, only in a plane normal to the direction, along which the laser beams stand in a row, and onto the stimulable phosphor sheet, and 
 optical devices, each of which is located between one of the laser diodes and the cylindrical lens and scatters the laser beam having been produced by the corresponding laser diode; wherein each of the laser diodes are located in an orientation such that a beam spread direction, which is normal to a junction plane, approximately coincides with the direction, along which the laser beams stand in a row. 
 
     
     
       8. A radiation image read-out apparatus, comprising:
 i) stimulating ray irradiating means for linearly irradiating stimulating rays through a cylindrical lens onto an area of a stimulable phosphor sheet, on which a radiation image has been stored, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored thereon during its exposure to radiation, 
 ii) a line sensor, which comprises a plurality of photoelectric conversion devices arrayed along the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, and 
 iii) sub-scanning means for moving the stimulable phosphor sheet with respect to the stimulating ray irradiating means and the line sensor and in a direction intersecting with a length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, 
 wherein the stimulating ray irradiating means comprises: 
 a plurality of laser diodes located such that laser beams, which have been produced by the laser diodes and act as the stimulating rays, stand in a row along the length direction of the linear area of the stimulable phosphor sheet exposed to the linear stimulating rays, each of the laser diodes being located in an orientation such that a beam spread direction, which is normal to a junction plane, approximately coincides with the direction, along which the laser beams stand in a row, 
 the cylindrical lens for converging each of the laser beams, which have been produced by the laser diodes, only in a plane normal to the direction, along which the laser beams stand in a row, and onto the stimulable phosphor sheet, and 
 optical devices, each of which is located between one of the laser diodes and the cylindrical lens and scatters the laser beam having been produced by the corresponding laser diode. 
 
     
     
       9. An apparatus as defined in  claim 6 ,  7 , or  8  wherein the plurality of the laser diodes are located such that the laser beams, which have been produced by the laser diodes adjacent to each other among the plurality of the laser diodes, stand in a row so as to have an overlapping region, at which the laser beams overlap each other. 
     
     
       10. The radiation image read-out apparatus as claimed in any one of  claims 6 – 8 , wherein the cylindrical lens comprises a single continuous cylindrical surface.